For a crisp outline, lip filler can be placed along the vermilion border to sharpen definition, reduce lipstick bleed

https://devinpgqi227.lucialpiazzale.com/lip-injection-doctor-q-a-expert-answers-to-common-questions

For a crisp outline, lip filler can be placed along the vermilion border to sharpen definition, reduce lipstick bleed, and enhance the Cupid’s bow.